/*
 * @Author: Jiraiya
 * @Date: 2020-03-13 15:12:20
 * @LastEditors: Jiraiya
 * @LastEditTime: 2020-03-13 17:51:40
 * @Description: 
 */
const a:number = 1

const b:HTMLElement|null = document.getElementById('app');

const c = history;

const d = window.alert

type Value = {
    length: number
}

type Arr = {
    [k in keyof History]: History[k] extends number ? k : never
}[keyof History]

const userAgent:{
    [k in Arr]: History[k]
} = {
    length: 1,
    state: 1
}

window.ECZN_FLAG;
console.log(ECZN_FLAG)
jQuery('#foo');

window.TEST = 2

const obj:IM = {
    a(){ return 'xx'}
}

type ISNumber = number


f(1,2,3)

greet('xx')